JPH0313431Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a vehicle wheel suspension system using torsion bars.

BACKGROUND ART Conventionally, cushions for wheel suspension systems for vehicles such as motorcycles that utilize the elastic force of torsion bars have been known. In such a wheel suspension system, for example, as disclosed in Japanese Utility Model Publication No. 58-2652 and Japanese Utility Model Publication No. 57-46644, the mounting portion of the torsion bar on the vehicle body side is fixed to the vehicle body in the axial direction by means of fixing means such as caulking or screwing. The torsion bars are firmly fixed so that they do not move in the circumferential direction, so when changing to a torsion bar of a different length in order to change the suspension characteristics of the wheel suspension system, it is necessary to make structural changes to the vehicle body or In practice, it is difficult to change because a fixing means is required, and even if it is possible to change it, the cost is high.

This invention was developed in view of the above circumstances, and has a structure that allows the cushioning characteristics to be easily changed by changing torsion bars of different lengths without making any structural changes to the vehicle body. The object is to provide a simple vehicle wheel suspension system.

In order to achieve this object, the present invention has one end of a torsion bar placed in a hollow vertical frame that constitutes a part of the vehicle body and extends substantially in the longitudinal direction of the vehicle body, so that one end of the torsion bar is prevented from rotating in the circumferential direction, but is prevented from rotating in the axial direction. The other end of the torsion bar extending outside the vertical frame is connected to a wheel support member that is swingably supported by the vehicle body. shall be.

Hereinafter, a first embodiment in which the device of the present invention is applied to a motorcycle will be described with reference to FIGS. 1 to 5.

The main body of the motorcycle body B is composed of a square pipe, and at the rear thereof, a wheel support member, that is, a rear fork 2 is pivotally supported so as to be able to swing up and down. The rear wheel 4 is rotatably mounted on the shaft.

The rear fork 2 is suspended by a suspension system S including a torsion bar 5.

The structure of the suspension system S will be explained below.

A pair of left and right hollow vertical frames 1, 1, which constitute a part of the vehicle body B and extend in the longitudinal direction thereof, are composed of square pipes with a square cross section, and the rear end surfaces of these vertical frames 1, 1 are open. There is.

The torsion bar 5 used as a cushion member of the suspension system S has a short cylindrical enlarged front end 5f and an enlarged front end 5r integrally formed at the front and rear thereof, and a male thread 6 is provided on the outer periphery of the enlarged front end 5f. The longitudinal frame 1 is engraved on the male thread 6.
The internal thread 7a of the holder 7, which has a bottomed square tube shape having the same shape as the inner peripheral surface shape of the holder 7, is screwed into the retainer 7, and the retainer 8 screwed onto the open end of the holder 7 is engaged with the rear end of the enlarged front end 5f. By doing so, the holder 7 is integrally tied to the enlarged front end portion 5f.

The torsion bar 5 has its enlarged front end 5f side inserted into the vertical frame 1 from its open rear end.
The rectangular holder 7 is fitted into the vertical frame 1 made of a square pipe, and is slidable in the axial direction but prevented from rotating in the circumferential direction. 1 is allowed to move in the axial direction, but rotation in the circumferential direction is prohibited.

The enlarged rear end portions 5r, 5r of the pair of left and right torsion bars 5, 5 are rotated by bearing members 9, 9 fixed to the opening rear ends of the left and right vertical frames 1, 1 with bolts 20, respectively. movably supported.
Furthermore, male serrations 10 are carved on the outer peripheries of the tip sides of the enlarged rear end portions 5r, 5r, and formed on the base ends 11a, 11a of the left and right swinging arms 11, 11, respectively. The female serrations 12, 12 are fitted together, and the torsion bars 5, 5 are twisted by the swinging of the swinging arms 11, 11. A retaining plate 13 that is engaged with the bearing member 9 is fixed to the outer end surface of each enlarged rear end portion 5r with a bolt 14, and this retaining plate 13 abuts against the outer surface of the base end 11a of the swing arm 11. , prevents the swing arm 11 from coming off.

The pair of left and right swing arms 11, 11 are mounted on the vehicle body B such that their tips 11b, 11b approach each other.
their tips 11
Upper ends 16a, 1 of left and right compression links 16, 16, which form a pair through universal joints 15, 15, are connected to b, 11b.
6a are connected. Left and right compression links 16, 16
extends approximately vertically, and their lower ends 16b, 1
6b is an opening 1 formed in the rear fork 2.
7 and 17 into the rear fork 2, and is rotatably connected to a support shaft 18 horizontally suspended in the rear fork 2.

Note that E in the figure is an engine suspended on the vehicle body B.

Next, the operation of the first embodiment of the present invention will be explained.

Due to the current movement of motorcycles, the rear fork 2
, if it swings up and down around the shaft support 3, the pair of compression links 16, 16 and the swing arm 1
The rear ends of the pair of torsion bars 5, 5 are twisted through the torsion bars 1, 11, thereby buffering and absorbing vibrations and shocks from the rear wheels 4.

By the way, if you want to change the cushioning characteristics of the rear wheel suspension system S, prepare a pair of torsion bars 5, 5 with different lengths or diameters, and fix holders 7, 7 to their large front ends 5f, 5f, respectively. The left and right vertical frames 1, 1 of the vehicle body B are fitted into and supported by the above-mentioned procedure, and their enlarged rear ends 5r, 5r are connected to the rear fork via the swing arms 11, 11 and the compression links 16, 16. Just connect it to 2. In this case, there is no need to make any structural changes to the left and right vertical frames 1, 1 of the vehicle body B, and no attachment parts are required.

FIG. 6 shows a second embodiment of the invention. This second embodiment has an enlarged front end 5 of a torsion bar 5.
This embodiment is different from the first embodiment in the means for connecting f and the holder 7. That is, the enlarged front end 5f
and the holder 7 screwed thereon, the holder 7
It is fixed by a bolt 19 screwed into the outer end surface of the holder.

In the above first and second embodiments, the torsion bar 5
Although the enlarged front end 5f of the holder 7 is screwed together with the holder 7, any means may be used to connect them, such as a serration connection or a fitting connection using polygonal portions.

A third embodiment of the present invention is shown in FIGS. 7 and 8. In this third embodiment, the present invention is applied to the left and right vertical frames 1', 1' of the vehicle body B formed by cylindrical pipes, and the large front end 5'f of the torsion bar 5' is formed into a polygonal (hexagonal) shape. shape),
On the other hand, the vertical frame 1' of the vehicle body B is formed into a polygonal part 1'a (hexagonal part) that can fit into the enlarged front end part 5'f over a certain length. The polygonal portion 1'a of the vertical frame 1' is set to a length that can be applied to a plurality of types of torsion bars 5' having different cushion characteristics.

As is clear from the above embodiments, according to the present invention, one end of the torsion bar is prevented from rotating in the circumferential direction within a hollow vertical frame that constitutes a part of the vehicle body and extends substantially in the longitudinal direction of the vehicle body. However, the other end of the torsion bar extending outside the vertical frame is connected to a wheel support member that is swingably supported by the vehicle body. Therefore, one end of the torsion bar can always be accurately supported by the common vertical frame regardless of the length of the torsion bar 5, and therefore, the torsion bar can be easily changed to another one having a different length. Furthermore, unlike conventional devices, there is no need to make any special structural changes to the vehicle body or prepare special mounting parts to make the change, so changing the torsion bar's cushion characteristics can be done quickly, easily, and at a low cost. It can be done at a cost. Further, since the vertical frame supporting one end of the torsion bar can be a hollow frame that constitutes a part of the vehicle body, the torsion bar mounting structure can be simplified and costs can be reduced accordingly. Furthermore, by arranging the vertical frame approximately in the longitudinal direction of the vehicle body, it is possible to set the vertical frame and torsion bar to be longer without particularly increasing the width of the motorcycle, which increases the degree of freedom in setting the cushioning characteristics. be able to.

[Brief explanation of the drawing]

1 to 5 show a first embodiment of the device of the present invention, FIG. 1 is a side view thereof, FIG. 2 is a cross-sectional view taken along the line of FIG. 1, and FIG. 3 is an exploded perspective view thereof. Figure 4 is an enlarged sectional view taken from Figure 2, and Figure 5 is an enlarged cross-sectional view of Figure 4.
6 shows the second embodiment of the present invention, and FIGS. 7 and 8 show the third embodiment of the present invention.
7 is a cross-sectional view of a part of the torsion bar inserted into the hollow frame, and FIG. 8 is a cross-sectional view taken along the line shown in FIG. 7. B...Vehicle body, 1,1'...Vertical frame, 2...
Rear fork as a wheel support member, 5, 5'...
...Torsion bar, 5f, 5'f...front end as one end, 5r...rear end as other end.

Claims (1)

[Scope of utility model registration request] One end portions 5f, 5'f of torsion bars 5, 5' are installed in hollow vertical frames 1, 1' that constitute a part of the vehicle body B and extend substantially in the front-rear direction of the vehicle body, although rotation in the circumferential direction thereof is prevented. The other ends 5r of the torsion bars 5, 5' are fitted and supported so as to allow sliding in the axial direction, and extend outside the vertical frames 1, 1'.
A wheel suspension system for a two-wheeled vehicle, characterized in that: is connected to a wheel support member 2 that is swingably supported by the vehicle body B.